Modern passenger aircraft, such as commercial jet airliners, commonly include a passenger support unit (PSU) located generally above each passenger's seat. The PSU typically includes a reading light, an air supply nozzle and an emergency oxygen mask for each passenger. The air supply nozzle facilitates control of the quantity and direction of air provided to the passenger.
Such contemporary air supply nozzles are typically adjusted by the passenger, so as to direct a stream of air upon the passenger's face and/or torso. This stream of air is refreshing and is intended to enhance the comfort of the passenger.
Although such contemporary air supply nozzles do typically enhance the comfort of a passenger during flight, such contemporary air supply nozzles suffer from inherent deficiencies which tend to detract from their overall utility. For example, the air flowing through an air supply nozzle and being directed toward the face of a passenger may contain undesirable airborne contaminants such as germs, dust and pollen.
The air circulation system of a commercial airliner typically has a particulate filter incorporated therein. However, such filters must be changed periodically in order to maintain their effectiveness. Although both the Federal Aviation Administration (FAA) and the aircraft manufacturer provide guidelines regarding the frequency with which aircraft air recirculation filters must be changed, there is no assurance that the airlines actually follow such guidelines.
Indeed, there is generally a substantial incentive for airline companies to disregard such guidelines, since more frequent filter replacement is costly, not only in terms of parts and labor but also in terms of the down time of the aircraft incurring such maintenance (during which the aircraft is clearly not contributing to the revenue of the airline).
There are documented cases of germs being transmitted among passengers during an airline flight. For example, in one incident reported by the Centers for Disease Control and Prevention, six of 257 passengers contracted tuberculosis, presumably from a single inflected passenger aboard the airliner.
As a further example, an airliner containing one person who had the flu was known to sit on the ground for approximately three hours. Three days later, 38 of the 54 people aboard the aircraft had contracted the flu.
Anecdotal evidence of this sort is abundant. Moreover, it is not difficult to understand that when a number of people are crowded together into a comparatively small space, such as that afforded by a commercial airliner, airborne contagiums will tend to be transmitted from one passenger to another.
In view of the foregoing, it is desirable to provide an air filter system which mitigates the exposure of a passenger to undesirable airborne contaminants. More particularly, it is desirable to provide such an air filter system which is configured so that a passenger may install and utilize the air filter system personally, so as to assure the adequacy of the filtration afforded thereby.